<template>
  <div class="xtx-carousel" @mouseenter="stop" @mouseleave="start">
    <ul class="carousel-body">
      <li v-for="(item,index) in sliders" :key="item.id" class="carousel-item " :class="{fade:activeIndex === index}">
        <RouterLink :to="item.hrefUrl">
          <img
            :src="item.imgUrl"
            alt=""
          />
        </RouterLink>
      </li>
    </ul>
    <!-- 左右箭头 -->
    <a @click="toggle(-1)" href="javascript:;" class="carousel-btn prev">
      <i class="iconfont icon-angle-left"></i>
    </a>
    <a @click="toggle(1)" href="javascript:;" class="carousel-btn next">
      <i class="iconfont icon-angle-right"></i>
    </a>
    <!-- 底部控制器 -->
    <div class="carousel-indicator">
      <span v-for="(item,index) in sliders" :key="item.id" @click="activeIndex = index" :class="{active:activeIndex === index }"></span>
    </div>
  </div>
</template>

<script>
import { ref, watch, onUnmounted } from 'vue'
export default {
  name: 'XtxCarousel',
  props: {
    sliders: {
      type: Array,
      default: () => []
    },
    // 是否自动轮播
    autoPlay: {
      type: Boolean,
      default: false
    },
    // 定时器切换时间
    duration: {
      type: Number,
      default: 3000
    }
  },
  setup (props) {
    // 下标
    const activeIndex = ref(0)

    const toggle = (number) => {
      const temp = activeIndex.value + number
      if (temp < 0) {
        activeIndex.value = props.sliders.length - 1
        return
      }
      if (temp > props.sliders.length - 1) {
        activeIndex.value = 0
        return
      }
      activeIndex.value = temp
    }
    let timeId = null

    const autoPlayFn = () => {
      clearInterval(timeId)
      timeId = setInterval(() => {
        toggle(1)
      }, props.duration)
    }
    watch(() => props.sliders, (val) => {
      if (val.length > 1 && props.autoPlay) {
        autoPlayFn()
      }
    }, { immediate: true })

    onUnmounted(() => {
      clearInterval(timeId)
    })

    // 鼠标移入停止播放
    const stop = () => {
      clearInterval(timeId)
    }

    // 鼠标移出继续播放
    const start = () => {
      if (props.autoPlay && props.sliders.length > 1) {
        autoPlayFn()
      }
    }
    return { activeIndex, toggle, stop, start }
  }
}
</script>

<style scoped lang="less">
.xtx-carousel {
  width: 100%;
  height: 100%;
  min-width: 300px;
  min-height: 150px;
  position: relative;
  .carousel {
    &-body {
      width: 100%;
      height: 100%;
    }
    &-item {
      width: 100%;
      height: 100%;
      position: absolute;
      left: 0;
      top: 0;
      opacity: 0;
      transition: opacity 0.5s linear;
      &.fade {
        opacity: 1;
        z-index: 1;
      }
      img {
        width: 100%;
        height: 100%;
      }
    }
    &-indicator {
      position: absolute;
      left: 0;
      bottom: 20px;
      z-index: 2;
      width: 100%;
      text-align: center;
      span {
        display: inline-block;
        width: 12px;
        height: 12px;
        background: rgba(0, 0, 0, 0.2);
        border-radius: 50%;
        cursor: pointer;
        ~ span {
          margin-left: 12px;
        }
        &.active {
          background: #fff;
        }
      }
    }
    &-btn {
      width: 44px;
      height: 44px;
      background: rgba(0, 0, 0, 0.2);
      color: #fff;
      border-radius: 50%;
      position: absolute;
      top: 228px;
      z-index: 2;
      text-align: center;
      line-height: 44px;
      opacity: 0;
      transition: all 0.5s;
      &.prev {
        left: 20px;
      }
      &.next {
        right: 20px;
      }
    }
  }
  &:hover {
    .carousel-btn {
      opacity: 1;
    }
  }
}
</style>
